Search Google Appliance

Patent Model for an Adder with Carry Invented by George Farmer

Description

This patent model for an adder has three concentric, linked discs that revolve on a central pivot. The bottom disc is numbered from 1 to 99 clockwise around its toothed edge, to represent hundreds and thousands. Above it is a smaller disc, also with teeth around the edge, numbered from 00 to 99 clockwise to represent units and tens. A window in the third, top, largest disc shows the result on the dials below. The largest disc is numbered from 1 to 100 around the edge. Atop this disc is a rotating arm. Moving the arm counterclockwise advances the inner disc proportionally, allowing one to enter numbers up to 99.

A lever extends from the side of the disc and bends over the top. If the arm rotates around a full 100 units, it pushes this lever, causing a carry. The lever also may be used to zero the hundreds and thousands digits. See U.S. patent 69,647 for “Improvement in Tallying Instrument.” According to the patent, the invention “relates to a new and improved method of registering or tallying the quantity of lumber measured, or keeping account of sums of money paid out or received . . .”

There was a George Farmer (born about 1831 in England, died 1880 in Saginaw, Michigan) who worked as a miller and shingle maker in Illinois and in Michigan. He is listed in the 1860 U.S. Census as living in Elmira in Stark County, Illinois, working as a miller. That same year he received a patent on August 21for an improvement in harvesters (#29685). By 1870, he was living in Saginaw, Michigan, still working as a miller. In the 1880 Census he is listed as a shingle manufacturer. He and his son, Albion, ran a shingle-making business in Saginaw under the name of George Farmer & Son. It is listed in the 1878 city directory for the town. The George Farmer who received the patent for this adder was a resident of Flint, which is near Saginaw.

Visitor Comments

Add a comment about this object

**Please read before submitting the form**

Have a comment or question about this object to share with the community? Please use the form below. Approved comments will appear on this page and may receive a museum response (but we can't promise). Please note that we generally cannot answer questions about your own artifacts or tell you how much they are worth.

Have a question about anything else, or would you prefer a personal response? Please visit our FAQ or contact page.

Personal information will not be shared or result in unsolicited e-mail. See our privacy policy.